correct tenses in Agent, Mix.Dep, GenServer docs

fix

Author: eksperimental

lib/elixir/lib/agent.ex

@@ -34,7 +34,7 @@ defmodule Agent do
           Agent.update(__MODULE__, &Set.put(&1, item))
         end
 
-        @doc "Reset the executed tasks and return the previous list of tasks"
+        @doc "Resets the executed tasks and return the previous list of tasks"
         def take_all() do
           Agent.get_and_update(__MODULE__, fn set ->
             {Enum.into(set, []), HashSet.new}

lib/elixir/lib/gen_server.ex

@@ -385,7 +385,7 @@ defmodule GenServer do
                   {:timeout, timeout} |
                   {:spawn_opt, Process.spawn_opt}
 
-  @typedoc "debug options supported by the `start*` functions"
+  @typedoc "Debug options supported by the `start*` functions"
   @type debug :: [:trace | :log | :statistics | {:log_to_file, Path.t}]
 
   @typedoc "The server reference"

lib/mix/lib/mix/dep.ex

@@ -2,7 +2,8 @@ defmodule Mix.Dep do
   @moduledoc false
 
   @doc """
-  The Mix.Dep a struct keeps information about your project dependencies.
+  The Mix.Dep struct keeps information about your project dependencies.
+
   It contains:
 
     * `scm` - a module representing the source code management tool (SCM)